In this study a novel method was developed to fabricate cadmium sulfide nanoparticles/multiwalled carbon nanotubes composite modified gold electrode (CdSNPs/MWCNTS/AuE) to measure trace amounts of norepinephrine(NE), indomethacin (IND), and uric acid (UA) simultaneously. Electrochemical investigations were carried out using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamprometery (CA) methods. Using DPV method under optimum condition, the NE anodic peak current represented a linear relationship in the two concentration ranges of 0.3 to 100.0 μM and 100.0 to 500.0 μM. For UA, the corresponding anodic peak current showed linear ranges from 0.5 to 100.0 μM and from 100.0 to 350.0 μM, and IND the corresponding linear range was between 2.0 to 80.0 μM, respectively. Detection limits have been calculated equal to 0.16 μM for NE, 0.09 μM for UA, and 0.46 μM for IND, respectively. The modified electrode has been applied for the determination of NE, UA and IND in human urine and blood serum with satisfactory results.
